Macrovascular Complications Likely When Patients on Hemodialysis Have Diabetic Retinopathy

The risk of macrovascular complications increases for some patients undergoing hemodialysis if they also develop diabetic retinopathy (DR), according to research published in the journal of Nutrition, Metabolism and Cardiovascular Diseases. Diabetic retinopathy increases the risk of acute ischemic stroke and peripheral artery disease (PAD) in patients with type 2 diabetes and end-stage kidney disease (ESKD) undergoing hemodialysis, according to the results of the retrospective cohort study.

Researchers evaluated data from 27,686 Taiwanese patients (mean age 66 years; 45.7% women) with type 2 diabetes who underwent at least 90 days of hemodialysis for ESKD between 2010 and 2014. After propensity score matching, the matched cohorts (n=18,328) had similar baseline characteristics, except that patients in the DR group tended to be younger compared with the non-DR group. The primary outcome was measured as the occurrence of macrovascular complications including acute coronary syndrome (ACS), acute ischemic stroke, or PAD. 

Patients in the DR group were more likely to experience macrovascular complications compared with patients without DR (28.9% vs 27.9%; crude HR, 1.06; 95% CI, 1.00-1.11; P =.0550). Although the risk of ACS did not differ between the groups, patients with DR were more likely to experience acute ischemic stroke (crude HR, 1.21; 95% CI, 1.10-1.34; P =.0001) and PAD (crude HR, 1.11; 95% CI, 1.01-1.21; P =.0266) compared with patients without DR.

Researchers report that their findings “offer new evidence that DR independently predicts acute ischemic stroke in patients with type 2 diabetes and ESKD who are undergoing hemodialysis. Retinopathy can therefore provide an early surrogate marker for cerebrovascular changes before any such changes become clinically significant.”

In contrast to previous research, this study did not find an association between DR and the occurrence of ACS. The mechanism for this finding is unclear because the risk factors for ACS do not differ from macrovascular complications such as acute ischemic stroke or PAD. However, the development of cardiac events in patients with ESKD is multifactorial and may be influenced by other pathogenic mechanisms.

Selection bias cannot be ruled out for this study because only a small proportion of patients with both chronic kidney disease and DR survive long enough to develop ESKD. An additional limitation is the lack of data for health-related behaviors such as smoking status or diet, which could influence these associations. Finally, it is possible that some patients in the non-DR group could have undiagnosed DR and the strength of the association could be stronger than reported.